Tiel East Drier and Nicer

Tiel East Drier and nicer

PREFERRED SCENARIO FOR THE FIGHTING OF WATER NUISANCE

It can be done. Water nuisance can be solved. With old familiar or innovative techniques we can fight the problems, also in swampy Tiel East. There is even space for more homes in this district on the Waal. This does require efforts on various fronts: fight the nuisance in the existing district, utilize the space around the high dike and create innovative building in the river foreland. Support of residents is essential, while realizing that not everyone can get what he or she wants. I often discuss this with residents. I have not met residents before who helped to think in such a willing and expert manner as in Tiel East. Professionally, not afraid of changes, with an eye for the interest of the district. That is a wonderful basis to make Tiel East drier and nicer.

Frans Tielrooij Ambassador of the Living with Water knowledge programme Tiel East Drier and nicer

PREFERRED SCENARIO FOR THE FIGHTING OF WATER NUISANCE

Municipality of Tiel Colophon This booklet is a publication of the municipality of Tiel and realized with the cooperation of the Rivierenland District Water Board. For more information please contact the project leader of “Wateropgave Tiel East”, Mrs Ine van den Hurk

Municipality of Tiel P.O. Box 6325, 4000 HH Tiel Telephone: 0344 63 71 11 E-mail: [email protected] www.tiel.nl

Text: Met Andere Woorden, Arnhem Design: Nies en Partners bno, Nijmegen Photography: AquaRo, www.aquaro.nl Arie van Vliet, Tiel Municipality of Culemborg Jan Bouwhuis, Tiel Mieke van Engelen, The Hague Rivierenland District Water Board Illustrations: Grontmij, Houten Roukens + Van Gils urban development/landscape + interior, Gouda Printed by: Jac. van Hardeveld, printers, Veenendaal Translated by: Interface Translators, Meteren

The translation was partly realized thanks to the financial aid of the province of Gelderland

August 2008 Preface

Tiel East is a special district in all respects. experts to help us think: Department for Public People love living there. Water nuisance is Works and Water Management, the province, also special here, although a less attractive the district water board, housing corporations, aspect. The district lies between the dikes project developers, consultancy firms and of the Waal and the Amsterdam-Rijn Canal. district residents. Each party sees the district in Problems with seepage water occur every- its own manner. This has resulted in animated where along the Waal, especially at high discussions and new views. Because no one water levels. A special feature is that the knows everything. The great involvement and problems occur here in a residential district. active participation have come as a pleasant surprise to me. As a result of climate change and higher water levels more seepage water will be created in In a few months’ time we have put dozens of the future. It is quite a task to find a solution ideas for Tiel East on the map. The municipality for this, while we want to build new houses in of Tiel will translate the best ideas into a this district as well. The Netherlands chooses preferred scenario, in the long term and in the to build in the existing towns as much as short term. Also in this respect the combined possible and to keep the surrounding landscape approach will be of decisive importance. If open. everybody contributes a little it will certainly become a success. There are no ready-made solutions available for the situation in Tiel East. That is why the mr. drs. W. Gradisen municipality has asked a large group of Alderman for the municipality of Tiel

Contents

The task for Tiel East 7 Water flows from high to low 15 The search for solutions 19 Preferred scenario 27 From rain barrel to water square 35 Weighed and found wanting 43 Next step 47 6 The task for Tiel East

Tiel East is boggy by nature. Not There is a high dike between Tiel East and the Another thing is that Tiel East has few ditches, surprising that cellars are sometimes Waal. Nevertheless the district and the river ponds or canals that can collect rainwater, are continuously in contact with one another, much less than elsewhere in the Netherlands. damp and streets are flooded. But by means of the water! The water in the river Almost all the rainwater flows directly into the to keep the district livable the water makes the groundwater below Tiel East heave. sewer. But in the event of a heavy shower it nuisance must really decrease. In If the water in the river rises, so does the cannot cope with the water mass and the water addition there are wishes to utilize groundwater. If the river water drops, so does treatment system also becomes overloaded. the groundwater. The Amsterdam-Rijn Canal Subsequently the water from the drain holes the district more intensively, for also pulls and pushes the groundwater in that will flow into the street. instance for additional houses, a manner . Especially in spring and autumn the community school, parks and squares. groundwater is high, almost up to street level. The high groundwater level and the overloaded The water issue and these other sewer create all kinds of problems. In some The wetness in Tiel East has worsened in the houses crawl spaces and walls become damp. wishes cannot be viewed separately. course of the years. That is because more The floor may start to rot or the wallpaper falls Drier, better and nicer are interrelated. houses and paved roads have been realized. down. After a heavy shower the streets are As a result rainwater can hardly sink into the flooded and are then impassable for a couple ground anymore. of hours.

7 8 Water The problems with water nuisance are not just Other districts of Tiel will also have to face going to disappear. On the contrary, without climate change. The risk of water nuisance is action the nuisance will actually become bigger. also increasing there. Solutions for the water Climate change will cause the river to rise problems in Tiel East must consequently be more often and drag up the groundwater as found as much as possible in the district itself. well. Heavy rains will also occur more often. Shifting it to other districts is not an option. So the sewer will have a harder time.

Tiel East is faced by three tasks: 1. The nuisance of the groundwater must decrease. The target is that the groundwater must be at a depth of at least seventy centimetres. 2. More water storage must be created to ‘park’ the superfluous rainwater temporarily. For the whole district thousands of cubic metres of storage are necessary. 3. The overloading of the sewer must be halved. That means that less rainwater is to flow to the sewer. In Tiel East six hectares of hardened surface, mainly roofs, must be disconnected from the sewer.

9 10 Houses, roads and public green spaces the district, such as childcare, healthcare and More people are coming to live in the surround- social work facilities. Both wishes may be ings of Tiel and new houses are needed for combined in a so-called community school. this. The houses are preferably built within the Clustering may be used to limit the traffic present boundaries of the town, so that the flows in the area. landscape in the surrounding area will not become clogged. The Tiel East district must In comparison to other residential districts Tiel offer space for an additional thousand houses. East does not have a generous share of parks, Some of them may be located at the Vijverberg squares and ponds. If more people come to and the Vijverterrein. But more houses must live in the district, the need for this will only be built in the existing residential areas as well. increase. This often requires a thorough renovation. In addition to low-rise building, multi-storey Space, space, space flats will be needed as well. The wishes for water, living, traffic and green spaces require extra space for each feature. More houses attract more traffic. The residents But the district remains the same size. That must be able to travel easily from their is why the space must be used efficiently, if homes to other destinations. That is why the possible for different wishes at the same time. municipality will build a new traffic route from That may be realized by building parking space the motorway to the Tiel East district. Along under the houses, for example, or by using the south side of the railway a new road will parks and ponds for water storage as well. also be built to make the station area more To be able to find those kinds of combined easily accessible. solutions, the municipality wants to tackle the various issues jointly as much as possible. The schools in Tiel East need more space and better accommodation. There is also a need for more facilities for parents and children in 11 12 Theo Peters ~ member of the Provincial Executive of Gelderland

“Tiel is the centre of this region. The surround- The water nuisance in Tiel East is substantial. ing area also uses the facilities such as the It is no picnic if you have water in your crawl theatre and the business parks. For the space. Elsewhere, on the other hand, we are residents of Tiel and the surrounding places bringing water to the area, to create lovely it is important that those facilities will remain. living environments. In Tiel East we must That is why most new houses are built in Tiel: ensure that people can also enjoy the water Tiel must remain the biggest. and are not troubled by it. And that is also possible, as long as we tackle water nuisance In the near future we will take decisions about and house building at the same time. We have houses in Tiel East. That cannot be done behind regarded water and living as separate issues your desk, you must have been there. For that for too long.” reason I have walked around and talked to residents. Some of the houses are no longer up to date. By refurbishing, occasional demolishing and new building the district may become nicer and more varied. I like it when the residents also join in the conversation, because they know best what harmonizes with their district. And the residents of Tiel East do have a special feeling for their district, they are enthusiastic.

13 14 Water flows from high to low

The Netherlands is rich in water. The first residents of Tiel built their houses This has attractive aspects, but also on a natural height along the Linge. At the beginning of the nineteenth century the small gives nuisance from time to time. town started to grow substantially. The natural The nuisance may differ greatly from height was soon full. For the new development place to place. In this way it will districts the town had to move to lower-lying sometimes get quite wet in Tiel East, areas around the centre. Originally they were bank areas of the Linge and the Waal. while within a stone’s throw the centre of the town remains as dry as a bone. Also within Tiel East there are drier and wetter places. How does the water finds its way?

15 Schematic cross-section of Tiel East

16 The Tiel East district is also built in a former Especially in spring and autumn the water in bank area of the Waal. The river itself no longer the river and the canal is high. In low sandy reaches that point. A heavy dike prevents this. parts of Tiel East the groundwater is then But a trickle of river water seeps under the dike almost at street level. If a heavy shower falls continuously, which is also called seepage. in such a period, there is a considerable risk The higher the river, the stronger the seepage of water nuisance. flow. Water will flow from high to low. Under the dike along the Amsterdam Rijn Canal seepage water also flows to Tiel East.

In this manner the groundwater in Tiel East rises and falls with the water level in the river and the canal. The subsoil of Tiel East consists of clay and sand. In the past the river left those materials in a jagged pattern: in one spot somewhat more clay, in another somewhat more sand. Groundwater flows easier through a parcel of sand than through a layer of clay. That is the reason why the nuisance differs from place to place.

17 18 The search for solutions

The more the merrier. This was how corporations and building companies have the search for solutions was started. studied the issues. Residents contributed their knowledge about the district. From resident to water expert, from

historian to urban developer, from The participants started working in four groups. dike warden to project developer. They were inspired in various manners, for A motley group of people started instance by a walk through Tiel East, a visit to water measures in Dordrecht or a digital to look for ideas to make Tiel East discussion. The groups presented their findings Some ideas could already be started tomorrow, drier and nicer. By combining the three times in a large meeting, so that they in a manner of speaking, while other measures knowledge of many different people could point out improvements and shortcomings require more time. the best results are created. to each other. Nothing was too outlandish at this stage. In the end only one map of Tiel East can become reality. To realize that map the municipality The task in Tiel East is not easy to solve. If that Each group has made a new map of Tiel East. had all the ideas thoroughly examined. Does were true, water nuisance would have been They include operations that can make the the idea actually solve the problems with water a thing of the past long ago. That is why the district drier and nicer. Jointly the groups have nuisance? Is it feasible? How much does it cost? municipality called in the assistance of a large collected dozens of ideas. All kinds of things And which ideas may be properly combined group of experts. The district water board, are included: permeable streets, a super-wide with one another? The best ideas of each group the province and ministries have joined in. dike, new canals and ditches, overgrown roofs have subsequently been combined into the Engineering firms, urban developers, housing and water squares. preferred scenario.

19 Scenario At Present:

Short-term solutions 20 Scenario RO -H2O: 21 Linking urban development and water Complete scenario:

Durable scenario for the future 22 Residents’ scenario 23 Community school, transformation transformation school, Community B Variant - infra and 3 Community school, transformation transformation school, Community A Variant - infra and The “Kleine Willemspolder” The “Kleine 3

4 Storing, draining and delaying the drainage the delaying and draining Storing, Draining 1 2 “When the water in the Waal is high, I have Damp crawl spaces are unhealthy, but that is forty centimetres of water in the crawl space no reason to demolish our homes. The residents at my home. Almost all the residents of Tiel are fiercely opposed to this. To enforce our have to deal with water nuisance, not only in arguments we have formed Bewonersbelangen Tiel East. So far we have had to learn to live Vogelbuurt Tiel (Residents Interest Group). with this. We have participated in the meetings of the municipality regarding the seepage problems and helped to think about solutions. The residents believe that the seepage water must be drained faster and wonderful ideas for this have been developed in the last few months. Now we are anxiously awaiting the municipality’s plan.”

Ab de Graaf ~ Chairman “Vogelbuurt Tiel” Residents Interest Group

24 Mirjam Cox ~ Resident of Tiel East

“Recently the water in the Waal was high and when this happens there is always a pool of water in our cellar two days later. We have impregnated the floor, but that does not help. We have even installed drainage in our back garden; otherwise nothing would grow there. We must even count ourselves lucky because the beams in our house do not get wet. That is because our house is built on a somewhat elevated sand ridge. With a small group of residents we have thought of solutions for the district. It is sometimes a Some time ago I read a notice of the munici- matter of small things. By removing street litter pality in the paper to participate in a discussion regularly, for example, you prevent the drain about water nuisance in Tiel East. I went there holes from becoming blocked. I would love it together with my father, because I would if they started operating the water tower again. dislike it very much if nobody from our street It can take away a lot of groundwater and the would be there. It is important to tell the experts water will be put to good use. But most of all I what life is like in this district. Otherwise we hope that no houses will be built in the Willems- will get plans that have been devised behind polder. I would really hate that. As soon as the desk and that perhaps do not harmonize you have passed the dike, you are in another with the culture of Tiel East. world, pure nature. That is really my niche!”

25 kaart 2015

2015 26 Legend see page 29 Preferred scenario

The best ideas for Tiel East are in Broadly four types may be distinguished: As good as possible the preferred scenario. The water • retain the water longer • ‘park’ the water temporarily in storage areas The preferred scenario is meant to tackle the nuisance will decrease in these • drain the water to areas that are less problems of the district in the best possible circumstances and the agreeable vulnerable manner. That means: features of the water will actually be • climate dike • solid: generously sized and natural emphasized. Space for more houses • durable: economical with the environment, Drainage of water often results in problems in energy and space and public green will be created as other places. The preferred solution is to re- • climate-proof: resistant against high river well. If all the parties decide to carry tain water or store it temporarily. But it takes drainage and heavy showers out the preferred scenario Tiel East a lot of time to make the retention and storage • good quality of living: visible water, varied will become drier and nicer. possible. The residents of Tiel cannot wait for surroundings that. Experts therefore recommend an approach • water conscious: living with water, on a in different steps. In the preferred scenario small scale and on a big scale The preferred scenario has been composed the solid measures, such as the opening up of of ideas that the experts and residents have watercourses, will be effected in the longer thought up in the past period. If the munici- term. Within about twenty years Tiel East will pality and other parties approve of it (the be durably climate-proof. In the short term the preparation of) the execution may be started. worst nuisance will disappear as a result of There is no universal remedy against water drainage in a part of the district. nuisance. That is why the preferred scenario consists of various operations.

27 2030 28 LEGEND Main infrastructure the business parks Westroijen and Latenstein 2. Wadis Connection between residential area and work area to Tiel East. This new entrance is part of a traffic Green spaces in Tiel East can store water by Separate cycle track bundle that will cross through the whole of changing them into wadis. The low-lying wadis Existing watercourses Tiel. Along the road there will be space for care collect the water in the event of heavy rainfall Broaden or construct watercourse Water drainage institutions, retail trade and a home furnishings and retain it for a while. In this manner it will Water square mall. The water must blend in properly with the reach the sewer less quickly. If it does not rain Landscape zone space around these facilities and businesses. for a long time, they will be dry. It is important Water square in combination with public green How this can be realized can be seen around that the wadis are an attractive part of a park Drainage in combination with separate drain pipes Wadi the building of the Rivierenland Water Board. or a playground. In the long term the wadis Wadi in combination with redevelopment of the exterior area There the water got a place in all kinds of may be connected with the planned new Ground to be raised lovely ways. watercourses. Climate dike Walking connection with the banks proceeding from the district The second watercourse is the “Doode Linge”, 3. Water squares which already exists but will become much Tiel East has space for three water squares: wider. This watercourse will moreover become east of the “Doode Linge” in the Station area, The six components of the preferred scenario more attractive with cycling tracks and foot- halfway up the Grotebrugse Grintweg and in are: paths and public green. In this way cyclists will the middle of the Vogelbuurt. If water squares be able to ride to the polders north of Tiel via lie on the roof of an underground car park, the 1. Open watercourses a new tunnel under the A15 and the Betuwe space will be used twice. Only when it rains very Open watercourses, such as ditches and all-freight railway . The third watercourse is the hard will the water squares be filled with water. ponds, have two advantages: they can store Spoorsingel, which will be located south of the The water flows there via gutters in the streets and drain rainwater. In the preferred scenario railway. Along the eastern part a separate cycle or green zones. The gutters of the new housing three new watercourses have been included. track and a walking area for the district will be also lead to the water square. This relieves the created. The western part will also get a green sewer. Water squares may become prominent The first watercourse will be located along the layout and separate cycling tracks and a new places in the district, with special playing new arterial road from the A15. This will run thoroughfare for a better connection with the facilities or another attractive layout. A beautiful via the extended “Laan van Westroijen” and station. integration requires proper consultation with all the landowners. 29 Schematic profile of a mound dike

High water criterion

Low water criterion

30 4. North-south drainage Kleine Willemspolder. In Tiel East the climate Kanaalstraat. In the course of time durable In the middle of Tiel East one or more water dike will get the form of a mould dike. The dike solutions will replace the drainage. connections are also necessary to drain off will be broadened by laying mounds against it. the excess water quickly to the circuit of open The mould dike can be built in stages. Along 7. Water-conscious building and living watercourses. Two tracks offer possibilities: the edge of the dike wadis will be realized. The starting point of the preferred scenario is • via the southern part of the Grotebrugse that each project in Tiel East will contribute to Grintweg (in combination with new 6. Drainage for quick result the reduction of the water nuisance from now pavements); In the event of heavy rain the water will now on. In this manner it can be prevented that Tiel • via the historic course of the Binnenboomse flow very quickly to gutters and drain holes. East will be in trouble again in a while. Big Wetering In a short time the sewer will have to cope and small projects may contribute in various With old maps the course of the Binnen- with much too much water. The preferred ways to the retention and storage of water. boomse Wetering can be traced. In the past scenario will therefore start with an operation Examples are vegetation roofs on new buildings this watercourse provided the water drainage that will slow down the water flow to the and permeable paving in parking places. The from the orchards in Tiel East. Restoration of sewer immediately: drainage. This operation residents of Tiel East can also play their part the watercourse makes the water issue more could be carried out tomorrow, in a manner by placing a rain barrel in the garden and by visible and more perceptible. of speaking. replacing paving with a lawn or plants.

5. Climate dike Ultimately drainage is not such a durable The river dike occupies a lot of space, but that solution. It is an artificial manner to dry the space can hardly be utilized. Building on or ground and the maintenance of drainage pipes around the dike is bound to many rules, is expensive. Nevertheless it seems necessary because the dike must remain strong and stable. to apply this measure in neighbourhoods By broadening the dike on both sides it becomes where the groundwater nuisance is very big: more stable and that offers new possibilities: a the surroundings of Nachtegaallaan, surround- high-lying walking area overlooking the river, ings of Hovenierslaantje, Vogelbuurt and the houses along the dike and building in the surroundings of Oude Medelsestraat and

31 32 Corné Nijburg ~ Living with Water

“Tiel has set itself a complicated task: the Proven solutions such as drainage and more water nuisance must be reduced, more houses surface water are included in the plans. Tiel must be realized and the quality of living of East may benefit a lot from this in the short the district must be improved. That is quite term. But new ideas are also projected for something. But the municipality has chosen the long term. A climate dike with houses for a vigorous approach of the problem that for instance, and water squares. With water other municipalities may benefit from as well. squares you attain a double advantage. Tiel has stuck out its neck by having everyone You solve a problem and you make people join in the conversation and by developing conscious of “living with water”. It is important plans together. that people know how it works, because the authorities cannot control the water for a What I particularly like is that the parties have hundred per cent.” first painted a picture for the long term and only subsequently worked back to what is possible Living with water is a knowledge incentive in the short term. The most acute problems programme with the following core messages: must be tackled at once, because the residents a new place for water, stimulating innovative are troubled by the water now and want to be water management, development and able to go for a walk now. But you must not strengthening of the knowledge infrastructure. regret it in the long term. (www.levenmetwater.nl)

33 34 From rain barrel to water square

In the preferred scenario there are Removal of the paving Wadi dozens of measures against water Rain that falls on paved ground flows much Wadi is the Arabic word for valley. A wadi is a quicker to the sewer than rain that falls on hollow where rainwater gathers and sinks into nuisance. They contribute to the unpaved ground. By removing the paving less the soil. This is how the wadi forms a buffer in retention, storage or drainage of rainwater will end up in the sewer or it will the event of superfluous rainfall. In general a water. This is how water nuisance reach the sewer less quickly. Where the ground- wadi is grown with grass or rush. The plants can be tackled on all fronts. water level is not too high the rainwater can ensure that the water becomes cleaner. A wadi sink into the soil of the unpaved ground. This can be created if paved ground is converted is how the load for the sewer will decrease into unpaved ground, for instance a green strip. Retention even further. This measure is possible by Vegetation roofs converting squares into parks and verges into Permeable paving Vegetation roofs are roofs that are grown with green strips or wadis. Private persons can Part of the paved ground consists of road for instance sedum, a succulent. These roofs also apply this measure by replacing paved surface. It is often not advisable to remove retain the rainwater for a long time before it garden terraces with grass, for example. In that paving. But the road surface may become flows to the sewer. The measure yields the the preferred scenario the removal of paving is permeable. The rainwater then flows between best result with application on large flat roofs, applied at many locations in the whole district. the joints of the paving bricks into the subsoil. for instance on business premises. The subsoil consists of lava rock for instance, which has a cleaning effect on the rainwater.

35 Storage Disconnecting Rainwater that falls on roofs usually ends up directly in the sewer via pipes. The District Water Board wants to disconnect part of the pipe system from the sewer and connect it to open watercourses. In that way the sewer and the sewage treatment system will be burdened less. At present disconnecting is still difficult, because there is only very little open water in Tiel East. If more watercourses are created it will become easier. In total the district water board wants to disconnect at least six hectares of paved surface.

36 Open watercourses Ditches and ponds give space to store water. When it rains the water does not flow to the sewer, but to the watercourses. It flows there via the ground or through pipes.

Rain barrel The well-known rain barrel is also a form of disconnecting. Rainwater that falls on the roof does not flow into the sewer, but ends up in the barrel. The water may subsequently be used for the garden, the flower boxes or to wash the car. The effect is small, but residents do play their part in this way.

37 38 Water square Water squares are low-lying squares that store water in the event of heavy showers. They temporarily change into a shallow pond. In dry times they are regular squares where people meet and children play.

Drain off Drainage By putting drain pipes in the subsoil the groundwater level may be controlled better. It is a prerequisite that drainage via the drainage pipes does not cause problems in other places, for instance because the watercourses into which they flow become overloaded. Research must provide more insight into this.

39 40 Huub van Heiningen ~ Historian and resident of Tiel

“Tiel is one of the oldest towns of the Nether- old watercourses again. The “Binnenboomse lands, perhaps the Romans already lived here. Wetering” for instance. It lies exactly on the Around 1500 the first watercourses were dug right spot, because in the past the water also to drain off seepage water to the “Doode Linge”. flowed from high to low. So we have had ages of experience with water management and we must take advantage of It is important that Tiel East will not be covered that. Without knowledge of the history you with buildings, because space is needed to cannot formulate policies. stockpile the water. The lowest points must certainly remain free, it would be better to In the sixties the municipality started to install build a water square there. But it will never sewers. The age-old watercourses were filled become dry as a bone in this district. I believe in, the water could after all flow to the sewer. that the municipality should forbid parquet In the beginning this also succeeded because floors and underfloor heating in vulnerable the “De Betuwe” factory pumped away houses. seepage water for the preparation of jam and People who come from the Randstad fruit juices. But when that business closed its conurbation simply do not know that now doors, things went wrong. When the river is and then it will get wet in Tiel”. high now, the seepage water flows into the cellars and in the street two days later. The sewer cannot cope with that mass of water. The best solution is obvious: open up those

41 42 Weighed and found wanting

A number of measures initially quay to keep the area behind the dike drier. Raising the ground level appeared attractive, but turned out But further on the nuisance actually increases. From a technical viewpoint raising the whole That is why this is not a sound solution. of Tiel East is the most effective solution to get to be unfeasible or impossibly dry feet. A raising of 0.50 to 0.75 meter would expensive upon further studying. Seepage screen along the dike suffice. But the whole district would have to be Those measures have not been The seepage water flows under the dike via demolished and rebuilt for this. That causes a included in the preferred scenario. a properly permeable sand layer. The seepage lot of inconvenience, it is very expensive and flow may be stopped by installing a seepage hardly feasible. That is why this solution was screen near the dike. The screen consists for abandoned. Raising the ground locally may be High kerbs example of sheetpile walls that must go all considered. A mound dike may be considered With high kerbs on both sides, streets can also the way to the bottom of the permeable layer. as a local raising. store water temporarily. At such a moment the In Tiel East the seepage screen would have to streets cannot be used by traffic and that may reach a depth of more than eighty metres. Pumping to the Amsterdam Rijn Canal cause congestions. This measure was dropped That is not a realistic solution. and the Waal for that reason. The point of departure is that Tiel East does Seepage ditch not shift the water problem to other areas or Seepage quay For a short time a seepage ditch seemed to be waters. Pumping to the Amsterdam Rijn Canal Seepage quays were often built in the past. good manner to collect seepage water directly means that this canal will have to cope with These are low quays lying at some distance near the dike. Calculations show however that even more water in times of high water levels. from the river dike. Seepage water is collected a seepage ditch actually attracts more water, That is not a durable solution with regard to in this area between the dike and the seepage also in the district. the climate.

43 44 Wadis on fallow land Impermeable layer Waal A few wadis have been included in the preferred A large part of the seepage water comes from scenario. In the preparation it was suggested the Waal. The seepage problem is tackled at that fallow lands offer space for even more the source by installing an impermeable layer wadis. That idea has not been incorporated at the bottom of the Waal. That is extremely because the construction of wadis costs a lot expensive and the problems may shift to other of money and it is uncertain in advance how areas. That is why this measure was abandoned. long they can remain on fallow lands. Impermeable layer Tiel East Impermeable layer Amsterdam-Rijn Canal In theory seepage water and groundwater can Part of the seepage comes from the Amsterdam- be stopped by installing an impermeable layer Rijn Canal. If there is an impermeable (clay) under the district, for instance a clay layer. layer at the bottom of the canal the seepage This will only have effect if the whole of flow to Tiel East will become smaller. This Tiel East is provided with such a layer. The measure tackles the problem at the source, but installation will cause much inconvenience, is very expensive. It is also difficult to check is hardly feasible and extremely expensive. whether the layer is indeed impermeable. It is also difficult to prevent that the covering layer gets damaged, on account of the fact that people sink ponds or plant trees. For this reason this measure was abandoned.

45 46 Next step

The preferred scenario is promising. and how they can pay it. When that has been Tiel is going to consult with other arranged, the parties will jointly draw up a programme of execution. It will record who parties whether the approach is takes on which work and when it will be feasible and affordable. If everybody finished. decides to participate, the ground will soon be broken. And then it is really going to happen. If the preferred scenario becomes reality, drainage pipes will soon be present in parts of the From rain barrel to water square, the water district. After that wadis, water squares, nuisance in Tiel East can be tackled in many watercourses and other solid measures will different ways. But the municipality of Tiel follow to make the district climate-proof. That cannot do this alone. Other parties play a role will undoubtedly cause a lot of inconvenience as well, for instance the province, the district during construction. But after that the reward water board, the Department of Waterways will follow: Tiel East nicer and drier. and Public Work, project developers, housing corporation, entrepreneurs and residents. The first step is that the main parties approve the preferred scenario. To take that decision they must know how much the scenario will cost

47 Bernard Teunissen ~ Member of the Rivierenland District Water Board “Water nuisance is a serious matter. I would hate so see the wallpaper coming off the walls at my home or the cellar under water. It is unhealthy to live in a damp house. That is why In addition we have called in the assistance I am happy that there are so many good ideas of different experts. The contribution of the now. We can make this work. residents was very useful in this respect. I am impressed by their willingness to think along. Seepage water has always been there, it simply The residents have enriched the plans with comes with a dike. It only becomes a problem their personal experience and knowledge when there are many buildings. Nowadays we about the past of the district. That complete, impose demands on new building: there must joint approach in Tiel East may be an example be sufficient space for water storage. But within to other municipalities. the new building projects in Tiel East that space is difficult to find, because the separate projects I expect that we can now soon take the step to are so small. The solution entered the picture execution. The responsible parties are going to when we started to look at Tiel East as a whole. make clear arrangements about that: who is Then a lot more turned out to be possible, also doing what and when will it be ready?” in the old districts.

48 Tiel East Drier and nicer

PREFERRED SCENARIO FOR THE FIGHTING OF WATER NUISANCE

Frans Tielrooij Ambassador of the Living with Water knowledge programme